The toolkit needs to have the display and font modules initialised;
pygame.init() would suffice.

screen=sgc.surface.Screen((640,480))

This creates a screen object, in much the same way as
pygame.display.set_mode() does. This is required for the toolkit to
function.

btn=sgc.Button(label="Clicky",pos=(100,100))btn.add(0)

This creates a new button widget, setting the label to ‘Clicky’ and the top-left
position of the widget to (100,100). The other line adds the button to the
screen, with the 0 specifying the focus order of the widget,
meaning the button will be the first widget to be focused
when the user hits the TAB key.

sgc.event(event)

This function sends an event through to the toolkit. This function should
appear in your event loop in order to handle all incoming events.

sgc.update(time)

This function should be called on each frame before the screen is updated.
It should be given the time passed since the last frame; this is usually
obtained from clock.tick().